Multiple data parts in multipart/form-data result in empty files/forms

[forana]

A POST body with one data part results in HTTP 200 with the expected contents:

--WjbdC_88SpbXfth8mh7N1d6vHDfUQU
Content-Disposition: form-data; name="file"; filename="test1353309547568909113txt"
Content-Type: application/octet-stream

There and Back Again
--WjbdC_88SpbXfth8mh7N1d6vHDfUQU
Content-Disposition: form-data; name="x"

y
--WjbdC_88SpbXfth8mh7N1d6vHDfUQU
Content-Disposition: form-data; name="m1a"

1
--WjbdC_88SpbXfth8mh7N1d6vHDfUQU--

response:

  ...
  "data": "", 
  "files": {
    "file": "There and Back Again"
  }, 
  "form": {
    "m1a": "1", 
    "x": "y"
  }, 
  ...

The same body (different boundary but correct headers) with two added data parts also results in HTTP 200, but with empty members:

--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA
Content-Disposition: form-data; name="file"; filename="test6297375454304944471txt"
Content-Type: application/octet-stream

There and Back Again
--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA
Content-Disposition: form-data; name="bytes"; filename="bytes"
Content-Type: application/octet-stream

The Talos Mistake
--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA
Content-Disposition: form-data; name="stream"; filename="stream"
Content-Type: application/octet-stream

Nerevar, Moon and Star
--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA
Content-Disposition: form-data; name="x"

y
--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA
Content-Disposition: form-data; name="m1a"

1
--Xya-QurXmcGYKeT0_-hPkzjeGNbmQbYw1numA--

response:

  ...
  "data": "", 
  "files": {}, 
  "form": {}, 
  ...

[forana]

Updated to have a correct multiple-data request (my bad) - the issue still occurs, however.

[forana]

Upon further research this is a duplicate of #102 - not actually related to having multiple files at all. Can be closed.

[piotr-dobrogost]

I think this is not duplicate of issue #102 as that issue is about Transfer-Encoding: chunked whereas this issue is about Content-Type: multipart/*. These are two different things.

[forana]

The actual issue here was the transfer-encoding. I thought it was the number of files, as that was the only difference I could immediately see, but I was able to disprove that by having it work with any number of files so long as the transfer-encoding wasn't chunked. The number of files isn't an issue, after all.

[sigmavirus24]

@piotr-dobrogost @forana this is a known problem with wsgi or werkzeug/flask iirc. I don't believe there are intentions to fix it though.